Hibernate optimistic Lock example

1. Create a new version field in the datasheet, either int or bigint

2. Add a version field to the JavaBean

Package Net.spring.model;

Import Javax.persistence.Column;
Import javax.persistence.Entity;
Import Javax.persistence.Id;
Import javax.persistence.Table;
Import javax.persistence.Version;

@Entity
@Table (name = "T_concurrency") public
class Concurrency {

	@Id
	private int Id;
	
    @Version
	private int Version;

	public int getId () {
		return ID;
	}

	public void setId (int id) {
		this.id = ID;
	}

	public int GetCount () {
		return count;
	}

	public void SetCount (int count) {
		This.count = count;
	}

	@Column
	private int count;

	public int getversion () {
		return version;
	}

	public void setversion (int version) {
		this.version = version;
	}

}

3.dao

	@Transactional (rollbackfor = runtimeexception.class,timeout=10)
	@Override public
	void subtract (int id) { Session
		
		session = NULL;
		
		try {
			session = This.gethibernatetemplate (). Getsessionfactory (). Getcurrentsession ();

			Query query = Session.createquery ("From Concurrency as u where u.id = '" + ID + "'");
			
			Concurrency C = new Concurrency ();
			c = (Concurrency) query.uniqueresult ();

			
			if (C.getcount () > 0) {
				//The first kind does not, not by Hibernate management, hibernate three states in line with, the direct HQL update optimistic lock not effective
				//sqlquery sqlquery = Session.createsqlquery ("Update t_concurrency set count=count-1 where id = '" + ID + "'");
				Sqlquery.executeupdate (); 
				
				C.setcount (C.getcount ()-1);
			}

		} catch (RuntimeException re) {
			throw new runtimeexception ();
			
		} finally {
			if (session! = NULL && sess Ion.isopen ()) {
				session.flush ();
				Session.clear ();}}}